Winds of Chaos

I have a player (a knight) who is wearing plate, over chainmail, over leather armour.
Is this allowed? Or just two different types of armour?

per pg. 300 of the Core book under "Flexible". Flexible armor may be worn under a layer of non-flexible armor and you gain the benefits of both. So in this case the chain and plate would offer combined protection and the leather would do nothing other than add encumbrance.

EDIT: I stand corrected. According yo the chart, soft leather can be worn under any other armor without restriction. So, by the rules, it looks like it possible.

Thank you very much